Is It Possible That God Would Disown Us?

If someone asked you, “If our eternal salvation is by faith alone and Jesus died for all our sins, then why does 1 Corinthians 6:9-11 say that if we live a sinful life, we’ll end up in hell?” could you answer them? Does God say that our salvation depends on our behavior, good or bad? Does He say that those who truly believe won’t live in continual sin? And why do Christians who’ve been Christians for decades have a difficult time answering these basic spiritual questions?